If you’ve eaten sushi, you’re no stranger to wasabi (wah-SAH-bee), the pungent green paste that’s served as a condiment. Said to translate as “mountain hollyhock” and widely known as “Japanese horseradish,” wasabi is part of the brassicaceae family, which includes cabbage and mustard.

As a plant, wasabi grows wild in mountain streams. It’s also cultivated in flooded terraces—a painstaking endeavor, since plants take several years to mature and water temperature must remain a constant 52 to 57 degrees F.

In Japan, wasabi is prepared in a variety of ways: Its gnarly roots are ground into the familiar greenish paste, flowers and leaves are turned into pickles, and leaves are battered and deep-fried. It’s frequently served with delicately steamed fish, tofu and custards. Since fresh wasabi is difficult to find in the United States, cooks generally purchase tubes of ready-to-use paste or wasabi powder that is mixed with water. But read the label: Sometimes what passes for “wasabi” is nothing more than common horseradish tinted with green food coloring. Store tubes in the fridge and keep the powder in a dark, dry spot in your cupboard. Stir it into mayo for a heady sandwich spread.

Health claims for wasabi abound. Like its cousin the cabbage, it helps protect against certain cancers. It’s also thought to prevent cardiovascular disease, and proponents claim it’s effective in treating maladies ranging from diarrhea to osteoporosis. One thing’s for certain: The heat is sure to clear your sinuses—the sensation known as the “wasabi rush” is enthusiastically celebrated by devotees of sushi.